/*
Language: Turtle
Author: Mark Ellis <mark.ellis@stardog.com>, Vladimir Alexiev <vladimir.alexiev@ontotext.com>
Category: common
Description: Terse RDF Triple Language for the semantic web 
Website: https://www.w3.org/TR/turtle/
*/

function(hljs) {
  var KEYWORDS = {
    keyword: 'base|10 prefix|10 @base|10 @prefix|10',
    literal: 'true|0 false|0',
    built_in: 'a|0'
  };

  var IRI_LITERAL = {// https://www.w3.org/TR/turtle/#grammar-production-IRIREF
    className: 'literal',
    relevance: 1, // XML tags look also like relative IRIs
    begin: /</,
    end: />/,
    illegal: /[^\x00-\x20<>"{}|^`]/, // TODO: https://www.w3.org/TR/turtle/#grammar-production-UCHAR
  };
  
  // https://www.w3.org/TR/turtle/#terminals
  var PN_CHARS_BASE    = 'A-Za-z\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02FF\u0370-\u037D\u037F-\u1FFF\u200C-\u200D\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD\u10000-\uEFFFF';
  var PN_CHARS_U       = PN_CHARS_BASE+'_';
  var PN_CHARS         = '-'+PN_CHARS_U+'0-9\u00B7\u0300-\u036F\u203F-\u2040';
  var BLANK_NODE_LABEL = '_:['+PN_CHARS_U+'0-9](['+PN_CHARS+'.]*['+PN_CHARS+'])?';
  var PN_PREFIX        = '['+PN_CHARS_BASE+'](['+PN_CHARS+'.]*['+PN_CHARS+'])?';
  var PERCENT          = '%[0-9A-Fa-f][0-9A-Fa-f]';
  var PN_LOCAL_ESC     = '\\\\[_~.!$&\'()*+,;=/?#@%-]';
  var PLX              = PERCENT+'|'+PN_LOCAL_ESC;
  var PNAME_NS         = '('+PN_PREFIX+')?:';
  var PN_LOCAL         = '(['+PN_CHARS_U+':0-9]|'+PLX+')(['+PN_CHARS+'.:]|'+PLX+')*(['+PN_CHARS+':]|'+PLX+')?';
  var PNAME_LN         = PNAME_NS+PN_LOCAL;
  var PNAME_NS_or_LN   = PNAME_NS+'('+PN_LOCAL+')?';
  
  var PNAME = {
    begin: PNAME_NS_or_LN,
    relevance: 0,
    className: 'symbol',
  };

  var BLANK_NODE = {
    begin: BLANK_NODE_LABEL,
    relevance: 10,
    className: 'template-variable',
  };

  var LANGTAG = {
    begin: /@[a-zA-Z]+([a-zA-Z0-9-]+)*/,
    className: 'type',
    relevance: 5, // also catches objectivec keywords like: @protocol, @optional
  };

  var DATATYPE =  {
    begin: '\\^\\^'+PNAME_LN,
    className: 'type',
    relevance: 10,
  };

  var TRIPLE_APOS_STRING = {
    begin: /'''/,
    end: /'''/,
    className: 'string',
    relevance: 0,
  };

  var TRIPLE_QUOTE_STRING = {
    begin: /"""/,
    end: /"""/,
    className: 'string',
    relevance: 0,
  };
  
  var APOS_STRING_LITERAL = JSON.parse(JSON.stringify(hljs.APOS_STRING_MODE));
  APOS_STRING_LITERAL.relevance = 0;

  var QUOTE_STRING_LITERAL = JSON.parse(JSON.stringify(hljs.QUOTE_STRING_MODE));
  QUOTE_STRING_LITERAL.relevance = 0;

  var NUMBER = JSON.parse(JSON.stringify(hljs.C_NUMBER_MODE));
  NUMBER.relevance = 0;

  return {
    case_insensitive: true,
    keywords: KEYWORDS,
    aliases: ['turtle', 'ttl', 'n3', 'ntriples'],
    contains: [
      LANGTAG,
      DATATYPE,
      IRI_LITERAL,
      BLANK_NODE,
      PNAME,
      TRIPLE_APOS_STRING, TRIPLE_QUOTE_STRING, // order matters
      APOS_STRING_LITERAL, QUOTE_STRING_LITERAL,
      NUMBER,
      hljs.HASH_COMMENT_MODE,
    ],
    exports: {
      LANGTAG: LANGTAG,
      DATATYPE: DATATYPE,
      IRI_LITERAL: IRI_LITERAL,
      BLANK_NODE: BLANK_NODE,
      PNAME: PNAME,
      TRIPLE_APOS_STRING: TRIPLE_APOS_STRING,
      TRIPLE_QUOTE_STRING: TRIPLE_QUOTE_STRING,
      APOS_STRING_LITERAL: APOS_STRING_LITERAL,
      QUOTE_STRING_LITERAL: QUOTE_STRING_LITERAL,
      NUMBER: NUMBER,
      KEYWORDS: KEYWORDS,
    }
  };
}